A cooling device for cooling air in a housing containing a heating element is for example disclosed in Japanese Patent Publication No. 10-190270 (U.S. Pat. No. 6,026,891) and No. 10-2686 (U.S. Pat. No. 6,119,767, U.S. Pat. No. 6,575,230). In the cooling device, a case is generally divided into an upper space and a lower space. A first heat exchanger for a low temperature fluid is provided in the upper space, and a second heat exchanger for a high temperature fluid is provided in the lower space.
A high temperature fluid is introduced in the lower space. In the lower space, heat exchange is performed between the high temperature fluid and a refrigerant flowing by the second heat exchanger. The refrigerant is boiled and evaporated by heat of the high temperature fluid, thereby cooling the high temperature fluid. On the other hand, a low temperature fluid having the temperature lower than that of the high temperature fluid is introduced in the upper space. In the upper space, heat exchange is performed in the first heat exchanger between the low temperature fluid and the refrigerant evaporated by the second heat exchanger. Thus, the refrigerant is condensed by transferring the heat to the low temperature refrigerant.
The case has a rectangular parallelepiped shape, for example. The case is mounted to the housing such that a main wall faces the housing.
In the above cooling device, to restrict heat from staying an upper location in the housing, a high temperature fluid inlet port is formed at an upper location of the case for introducing the high temperature fluid into the case. Also, the upper space for the low temperature fluid is partly used for defining a passage to introduce the high temperature fluid to the lower space of the case. Namely, the upper space of the case is divided into the high temperature fluid passage and a low temperature fluid passage in a thickness direction that is perpendicular to the main wall. Therefore, it is difficult to reduce the thickness of the case to maintain the high temperature fluid passage on a back side of the low temperature fluid passage in the upper space of the case.